Percutaneous access systems and methods

ABSTRACT

Percutaneous access systems, including trocars, for accessing desired locations within a subject&#39;s body through the subject&#39;s skin or other tissues that are configured to minimize incision sizes are disclosed. Such a percutaneous access system includes a cannula and an obturator. The cannula includes a passageway with a tapered section and an expandable section at its distal end. The expandable section may include leaves that are configured to extend radially outward as an elongated instrument that has an outer diameter that exceeds a minimum relaxed inner diameter of the tapered section of the passageway is forced through the tapered section. Methods for using such a percutaneous access system, including medical procedures, are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.No. 16/460,994, filed on Jul. 2, 2019 and titled PERCUTANEOUS ACCESSSYSTEMS AND METHODS (“the '994 Application”), now U.S. Pat. No.11,141,192, issued Oct. 12, 2021, which is a continuation of U.S. patentapplication Ser. No. 14/946,514, filed on Nov. 19, 2015 and titledPERCUTANEOUS ACCESS SYSTEMS AND METHODS (“the '514 Application”), nowU.S. Pat. No. 10,335,195, issued Jul. 2, 2019. The entire disclosures ofthe '994 Application and the '514 Application are hereby incorporatedherein.

TECHNICAL FIELD

This disclosure relates to percutaneous access systems and, morespecifically, to percutaneous access systems, including trocars, withcannulas that are configured to minimize the dimensions of an openingthrough skin. Additionally, this disclosure relates to methods for usingpercutaneous access systems.

RELATED ART

Trocars have been employed in the medical field for many years. A trocartypically includes a cannula (a hollow tube), an obturator with asharpened tip that extends through a channel of the cannula, and a sealbetween the obturator and the cannula. The sharp top of the obturator,when extended from a distal end of the cannula, is configured to form anincision, or opening, through a subject's skin or other tissues and,thus, to be introduced into a site of interest (e.g., a location throughwhich a laparoscopic procedure is to be performed, etc., such as acavity, a blood vessel, etc.) within the subject's body. Once the sharptip of the obturator and the distal end of the cannula have beenpositioned at the location of interest, the obturator may be removedfrom the channel of the cannula and the laparoscopic procedure may thenbe performed through the cannula.

The distal end of the cannula of a conventional trocar typically has afixed outer diameter, which is usually consistent with the outerdiameter of a remainder of the cannula. Thus, the size of the incisionmade by the obturator must accommodate the outer diameter of thecannula. In embodiments where the channel of the cannula mustaccommodate medical instruments with relatively large outer diameters, acannula with a larger outer diameter is required and, thus, a relativelylarge incision must be made through the subject's skin or other tissues.

Large incisions are typically undesirable for a number of reasons. Forexample, larger incisions are typically more unsightly than smallerincisions, take longer to heal than smaller incisions, result in anundesirable amount of scar tissue relative to the amount of scar tissuegenerated as a subject heals from a smaller incision, and pose a greaterrisk of infection from the procedure and as the subject heals from theprocedure.

SUMMARY

This disclosure, in various aspects, relates to enhancements to existingprocedures that involve the use of trocars. In addition, this disclosurerelates to “percutaneous access systems,” including trocars, foraccessing desired locations within a subject's body through thesubject's skin with minimal incision sizes.

In one aspect, a percutaneous access system comprises a trocar with atapered cannula that includes an expandable section at its distal end.In some embodiments, the cannula may include an elastomeric sheath overa proximal portion of the expandable section. The expandable section mayinclude an external taper from a relatively large outer diameter at aproximal location to a smaller outer diameter at a more distal location,as well as an internal taper (along an internal passageway that extendsthrough the cannula) from a relatively large inner diameter at aproximal location to a smaller inner diameter at a more distal location.Slits (e.g., laser cuts, etc.) along the length of the expandablesection at various locations around the circumference of the expandablesection may separate the expandable section into a plurality ofexpandable elements (each of which is also referred to herein as a“leaf”), and may enable expansion of the expandable section.

In addition to the tapered, expandable cannula, a trocar according tothis disclosure includes an obturator. The obturator is configured to beinserted from a proximal side of the cannula into and through thecannula, such that a distal tip of the obturator will extend through andprotrude from a distal end of the cannula. A distal tip of the obturatormay be configured to pierce the skin and/or other tissues of a subject'sbody to provide access to a desired location within the subject's body.More specifically, the distal tip of the obturator may comprise asharpened point or a sharpened edge, which may be configured to pierceskin or other tissues of the subject and, thus, to form an incision, oropening, and, optionally, a pathway through the skin and/or one or moreother tissues of the subject's body. In some embodiments, an outerdiameter of the obturator may be the same as or slightly smaller than asmallest inner diameter of the cannula, enabling the obturator to becompletely introduced into and assembled with the cannula, and toprotrude from a distal end of the cannula, without causing the distalend of the cannula to expand. Thus, the obturator may form an incisionand the unexpanded, tapered distal end of the cannula may follow thedistal tip of the obturator into the incision. Alternatively, theobturator may have an outer diameter that exceeds the smallest innerdiameter of the cannula, in which case the obturator may be proximallywithdrawn through the cannula to enable the distal end of the cannula tocontract as it is advanced distally into the incision.

The obturator may be removed from the cannula to make way for anotherelongated instrument, such as a laparoscopic surgical instrument, aguidewire, a sheath, a tube and/or a catheter. An outer diameter of theelongated instrument may be less than the relatively large innerdiameter of the cannula but, in some embodiments, greater than thesmaller inner diameter of the cannula. As an elongated instrument withan outer diameter that exceeds the smaller inner diameter of the cannulais introduced distally through the internal passageway through thecannula, the elongated instrument will force leaves of the expandablesection outward, putting the expandable section into an expanded state,in which both the inner diameter and the outer diameter of the distalportion of the expandable section of the cannula are effectivelyincreased. In some embodiments, the portion of the internal passagewayof the cannula that extends through the expandable section may beconfigured to open gradually as the distal end of the elongatedinstrument moves therethrough, with the expandable section only openingcompletely when the distal end of the elongated instrument is coincidentwith the distal end of the cannula. As the outer diameter of theexpandable section increases, an opening through any tissues (e.g.,skin, etc.) in which the expandable section is located may be dilated,or enlarged.

When a portion of the elongated instrument that has forced the leaves ofthe expandable section of the cannula outward is removed from theexpandable section (e.g., withdrawn from the internal passageway in aproximal direction, etc.), the leaves may be free to collapse, enablingthe expandable section of the cannula to return to its initial collapsedstate. The presence of an elastic sleeve, if any, around the proximalportion of the expandable section may ensure that the leaves return totheir initial orientations and, thus, that the expandable sectionreturns to its collapsed state. As the expandable section of the cannulacollapses, the opening(s) in tissues through within which the expandablesection resides may also constrict, or return to its (their) initial,smaller size(s).

In another aspect, a percutaneous access system, such as a trocar, mayinclude a cannula with an expandable section, an obturator (e.g., arigid obturator; a flexible, or bendable, obturator; etc.) insertableinto and/or movable through the cannula, an optional elongatedinstrument (e.g., a wire, a sheath, a tube, a catheter, a laparoscopicsurgical instrument, etc.), and a housing for maintaining a relationshipbetween the cannula and the obturator or other elongated instrument. Thehousing may include a distal hub secured to a proximal end of thecannula, a proximal hub configured to engage a proximal portion of theobturator and/or a location along a length of another elongatedinstrument (e.g., a wire, a sheath, a tube, a catheter, a laparoscopicsurgical instrument, etc.), and a main body to which the distal hub andthe proximal hub are secured. The distal hub may be fixedly secured inplace relative to a distal side of the main body. In some embodiments,the proximal hub may be rotatably secured in place relative to aproximal side of the main body. More specifically, a retaining ring maybe configured to be fixedly secured in place relative to the proximalside of the main body of the housing, while holding the proximal hub inplace, and enabling the proximal hub and, thus, the elongated instrumentto rotate relative to the main body, the distal hub and the cannula. Insome embodiments, the proximal hub may be configured to be graspedbetween an individual's thumb and finger (e.g., index finger, etc.) toenable manual manipulation of the elongated instrument. One or both ofthe retaining ring and the main body may be configured to enable orcause the proximal hub and the elongated instrument to rotate and/orotherwise move relative to the main body in a controlled fashion (e.g.,along a helical thread, along a spiral groove, etc.). In someembodiments, the retaining ring and/or the main body may be configuredin a manner that enables the proximal hub to lock in one or morepositions (e.g., in a proximal position (i.e., with the elongatedinstrument fully withdrawn (proximally) into the cannula), in one ormore intermediate positions, in a distal position (i.e., with theelongated instrument fully extended (distally) from the cannula), etc.).The proximal hub can be locked into a distal position as the distal endof the elongated instrument protrudes from the distal end of thecannula.

The proximal hub of a percutaneous access system according to thisdisclosure may include a passage extending through its length. Thepassage through the proximal hub may be continuous with and, thus,communicate with the internal passageway through the cannula. Thepassage through the proximal hub may be configured to receive anelongated instrument that may also extend into and/or through theinternal passageway through the cannula. In some embodiments, theproximal hub (e.g., the passage therethrough, etc.) may be configured toengage the elongated instrument and, thus, cause the elongatedinstrument to rotate about its longitudinal axis as the proximal hub isrotated about the longitudinal axes of the housing and/or the cannula.

An access technique according to this disclosure may include introducingan obturator of a trocar into and through a cannula of the trocar insuch a way that a distal end of the obturator, which is configured tocut and/or puncture a subject's skin, protrudes from (and, thus, beyond)a distal end of the cannula. With a longitudinal position of theobturator fixed relative to a longitudinal position of the cannula, theobturator may be positioned against the subject's skin at a locationthat is intended to form an incision, or opening, and provide access toa site of interest, and then forced into and at least partially throughthe subject's skin. The obturator and a distal and of the cannula maythen be advanced to a desired location within the subject's body (e.g.,a vascular location, a non-vascular location, etc.), creating a paththat will provide access to the desired location. Once the desiredlocation has been accessed, the obturator may be withdrawn into thecannula and from the percutaneous access system. Another elongatedinstrument, such as a laparoscopic surgical instrument, a wire, asheath, a tube and/or a catheter, may be introduced into and through theinternal passageway through the cannula. In embodiments where an outerdiameter of the elongated instrument exceeds the smaller inner diameterof the expandable section of the cannula, movement of the elongatedinstrument distally through the expandable second may cause theexpandable section to expand, which may dilate, or stretch, one or moreopenings in tissues through which the expandable section extends ratherthan requiring the formation of a larger opening or the use of a morecomplex conventional dilation system.

Other aspects, as well as features and advantages of various aspects, ofthe disclosed subject matter will become apparent to those of ordinaryskill in the art through consideration of the ensuing description, theaccompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a side view of an embodiment of percutaneous access systemaccording to this disclosure, which percutaneous access system comprisesa trocar;

FIG. 2 is an exploded view showing various elements of the embodiment ofpercutaneous access system of FIG. 1, in which the elongated instrumentcomprises an obturator that is configured to be assembled with a housingand a cannula of the percutaneous access system;

FIGS. 3 and 4 provide isometric view of the embodiment of percutaneousaccess system shown in FIG. 1;

FIGS. 3A and 4A provide enlarged view of the sections identified as “A”and “B” of FIGS. 3 and 4, respectively;

FIG. 5 illustrates an embodiment of an internal passageway through anexpandable section of a cannula, which includes at least one taper;

FIGS. 6 and 7 are perspective views of an expandable section of thecannula and an elastic sleeve that surrounds a proximal portion of theexpandable section, respectively showing the expandable section incollapsed and expanded states; and

FIGS. 8A-8C illustrate an embodiment of percutaneous access system inwhich the housing and cannula are used in conjunction with an elongatedinstrument, such as a laparoscopic surgical instrument, a wire, asheath, a tube, or a catheter.

DETAILED DESCRIPTION

With reference to FIGS. 1-4, 3A and 4A, an embodiment of a percutaneousaccess system 10 according to this disclosure is depicted. The depictedpercutaneous access system 10 comprises a trocar, which includes acannula 20, a handle 40 and an obturator 50. The handle 40, which issecured to the cannula 20, may include a main body 60, a distal hub 70and a proximal hub 80. The obturator 50 is configured for assembly withthe handle 40 and the cannula 20.

The cannula 20 may be configured similarly to the micro-taper needle ofU.S. Pat. No. 7,803,142, the entire disclosure of which is incorporatedherein by this reference. More specifically, the cannula 20 may includea proximal end 22 and a distal end 24. An expandable section 25 mayextend proximally from the distal end 24 of the cannula 20 to anintermediate location along its length. The expandable section 25 mayinclude a plurality of slits 26 (FIGS. 3, 5, 6, and 7) that extendthrough the thickness of a wall of the cannula 20, which extend alongthe length of the expandable section 25 and are spaced apart atdifferent locations around the circumference of the expandable section25. The slits 26 may separate the expandable section 25 into a pluralityof expandable elements, which are also referred to herein as “leaves”27.

In some embodiments, such as that depicted by FIGS. 1 and 2, theexpandable section 25 may comprise a tapered portion of the cannula 20.More specifically, a proximal portion of the cannula 20 may have aconstant outer diameter (i.e., it may be straight, or untapered), whilethe expandable section 25 or a portion thereof is tapered. Asillustrated, an outer diameter of the cannula 20 may taper from arelatively large dimension at a proximal side of the taper (e.g. at aproximal side of the expandable section 25, etc.) to a smaller dimensionat a distal side of the taper (e.g., at the distal end 24 of the cannula20, etc.).

As illustrated by FIG. 5, an inner diameter of an expandable section 35of an internal passageway 30, which resides within a tapered portion(e.g., the expandable section 25, etc.) of the cannula 20, may alsoinclude one or more tapers. In such an embodiment, as an elongatedinstrument 100 (FIGS. 7-8C) (e.g., a laparoscopic surgical instrument, awire, a catheter, a tube, a sheath, etc.) with an outer diameter thatexceeds the inner diameter of any portion of the expandable section 35moves distally through the internal passageway 30, the elongatedinstrument 100 will force the leaves 27 outward, expanding theexpandable section 25. Expansion of the expandable section 25 includesan effective expansion of the inner diameter of the expandable section35 of the internal passageway 30 within the expandable section 25 of thecannula 20 and an increase in the outer diameter of the expandablesection 25.

In some embodiments, tapering of the expandable section 35 of theinternal passageway 30 that resides within the expandable section 25 ofa cannula 20 may be varied. For example, the expandable section 35 ofthe internal passageway 30 may include at least one tapered portion andat least one straight portion. As another example, the expandablesection 35 of the internal passageway 30 may include portions withdifferent tapers. Without limitation, FIG. 5 illustrates an embodimentin which a proximal taper 36 of the expandable section 35 of an internalpassageway 30 is configured to cause the expandable section 25 (FIGS.1-4, 3A and 4A) of the cannula 20 (FIGS. 1 and 2) to expand in such away that an outer diameter of the distal end 24 (FIGS. 1 and 2) of thecannula 20 increases to a first dimension, while a distal taper 37(which may comprise an inner diameter that decreases from a proximalside of the distal taper 37 to a distal side of the distal taper 37) ofthe expandable section 35 of the internal passageway 30 may enable theexpanded outer diameter of the distal end 24 of the cannula 20 to remainthe same while an elongated instrument 100 (FIGS. 8A-8C) continues toadvance distally through the internal passageway 30. Of course, othervariations in the manner in which the expandable section 35 of theinternal passageway 30 through the expandable section 25 of a cannula 20tapers, as well as variations in the outer diameter of an elongatedinstrument 100 (FIGS. 7-8C) that may be moved through the expandablesection 35 of the internal passageway 30, may enable the expandablesection 25 of the cannula 20 to expand and/or collapse in any desiredfashion as the elongated instrument 100 moves through the internalpassageway 30, or at least through the expandable section 35 of theinternal passageway 30.

With returned reference to FIGS. 1-4, 3A, 4A, and 7, a percutaneousaccess system 10 may include an elastic sleeve 28 that surrounds atleast a proximal portion of the expandable section 25 of the cannula 20.In some embodiments, the elastic sleeve 28 may extend from a location ator adjacent to the proximal end 22 of the cannula 20 to a locationsomewhat proximal to the distal end 24 of the cannula 20. Withoutlimitation, a distal end 29 of the elastic sleeve 28 may be locatedabout 1 cm or about a quarter inch (¼ inch) proximal to the distal end24 of the cannula 20.

The elastic sleeve 28 may be formed from a material that will enable itto conform to the shape and dimensions of the portions (e.g., a proximalportion of the expandable section 25, etc.) of the cannula 20 over whichit is positioned. The material of the elastic sleeve 28, as well as itsdimensions (e.g., its thickness, etc.), may enable the elastic sleeve 28to expand while the expandable section 25 expands, and to contract uponremoval of an expansion force (e.g., partial or complete removal of anelongated instrument 50, etc.) from the expandable section 25. As theelastic sleeve 28 contracts, it may force the leaves 27 of theexpandable section 25 radially inward toward or to their originalpositions, thereby collapsing the expandable section 25 and, when theexpansion force is totally removed therefrom, enabling the expandablesection 25 to return to its collapsed state. The material from which theelastic sleeve 28 is formed, along with its dimensions, may also enableit to maintain its integrity when expanded and contracted, withoutsignificantly impeding insertion of the cannula 20 into and through asubject's skin. Suitable materials for use as the elastic sleeve 28include, but are not limited to, dip molded elastomers and heat shrinkelastomers, including elastomeric fluoropolymers. The thickness of theelastic sleeve 28 may be about 0.00025 inch to about 0.0025 inch (e.g.,about 0.001 inch, etc.). FIGS. 6 and 7 respectively show an expandablesection 25 of the cannula 20 in collapsed and expanded states.

As an alternative to the elastic sleeve 28, or in addition thereto, theexpandable section 25 of the cannula 20 may be formed from a materialthat will resiliently return to its original shape (i.e., that willenable the leaves 27 to collapse) once an expansion force (e.g., anelongated instrument, etc.) is partially or completely removed from theexpandable section 25.

As illustrated by FIGS. 2, 3, 3A, 4 and 4A, the obturator 50 of a trocarembodiment of a percutaneous access system 10 according to thisdisclosure includes a proximal end 52 and a distal end 54. The distalend 54 may be configured to fit within the internal passageway 30through the cannula 20 and to be moved, or translated, along a length ofthe internal passageway 30, including through the expandable section 35of the internal passageway 30. In the depicted embodiment, an outerdiameter of a portion of the obturator 50 that resides within and/or isconfigured to be positioned within at least a portion of the internalpassageway 30 through the cannula 20—i.e., a distal portion of theobturator 50—is uniform. In the embodiment of percutaneous access system10 illustrated by FIGS. 1-4, 3A and 4A, the obturator 50 has an outerdiameter that is the same as or slightly less than a smallest innerdiameter of the internal passageway 30 through the cannula 20. Thus, asthe obturator 50 is introduced into and through the internal passageway30, and as the obturator 50 resides within the internal passageway 30,the obturator 50 will not cause the expandable section 25 of the cannula20 to expand, thus enabling the expandable section 25 of the cannula 20to remain in the collapsed state shown in FIGS. 5 and 6.

A proximal end 52 of the obturator 50 may be configured to engage or tobe engaged by a corresponding feature of the handle 40 of thepercutaneous access system 10. Without limitation, the proximal end 52of the obturator 50 may be configured to engage or to be engaged by theproximal hub 80 of the handle 40 of the percutaneous access system 10.

As illustrated by FIG. 7, an elongated instrument 100 (e.g., a wire, asheath, a tube, a catheter, etc.) with an outer diameter that exceedsthe minimum inner diameter of the expandable section 35 of the internalpassageway 30 through the cannula 20 will cause the expandable section25 of the cannula 20 to expand. As the outer diameter of such anelongated instrument 100 is greater than the minimum inner diameter ofthe expandable section 35 of the internal passageway 30, introducing adistal end 104 of the elongated instrument 100 into the expandablesection 35 will force to the leaves 27 of the expandable section 25 ofthe cannula 20 radially outward, enlarging the inner diameter of theexpandable section 35 of the internal passageway 30 and expanding theouter diameter of the expandable section 25 of the cannula 20,particularly at its distal end 24.

Referring again to FIGS. 1-4, a further description of the manner inwhich the cannula 20 and the obturator 50 are assembled with oneanother, and a description of the manner in which the cannula 20 and theobturator 50 function relative to one another are provided. It should benoted that the teachings provided hereinafter are also applicable to theuse of an elongated instrument 100 (FIGS. 7-8C) with the cannula 20, inplace of the obturator 50.

The handle 40 of the percutaneous access system 10 may include a distalhub 70 at the proximal end 22 of the cannula 20 that may facilitateassembly of the obturator 50 or another elongated instrument 100 (FIGS.7-8C) with the cannula 20. Specifically, the distal hub 70 may include achannel 76 that, at a distal side 74 of the distal hub 70, receives theproximal end 22 of the cannula 20. At a proximal side 72 of the distalhub 70, the channel 76 may be configured to enable alignment of thedistal end 54 of the obturator 50 (or of another elongated instrument100 (FIGS. 7-8C)) with the internal passageway 30 through the cannula20.

The proximal side 72 of the distal hub 70 may also be configured tocouple the cannula 20 to the main body 60 of the percutaneous accesssystem 10. In a specific, but non-limiting embodiment, the proximal side72 of the distal hub 70 may be configured to be received within anaperture 65 at a distal side 64 of the main body 60 of the handle 40,and may be fixedly coupled to the main body 60 (e.g., mechanically, witha suitable glue or cement, etc.).

The proximal side 62 of the main body 60 of the handle 40 may beconfigured to receive or otherwise engage a proximal hub 80 of thehandle 40. More specifically, the distal portion 84 of the proximal hub80 may be configured for receipt by an enlarged proximal portion of apassage 66 through the main body 60 of the percutaneous access system10. With the main body 60 and the proximal hub 80 configured in thismanner, when the proximal hub 80 is assembled with the main body 60, achannel 86 that extends through a length of the proximal hub 80 isaligned with and communicates with the passage 66 through the main body60 and, thus, with the channel 76 that extends through the distal hub 70and the internal passageway 30 that extends through the length of thecannula 20.

In the depicted embodiment, a retaining ring 69 may be configured tohold a distal-most end of the distal portion 84 of the proximal hub 80in place within the passage 66 through the main body 60.

In some embodiments, features 85 (e.g., one or more spiral protrusions,or threads, etc.) on an outer circumference of the distal portion 84 maycooperate with (e.g., be received by, etc.) cooperating features 67(e.g., one or more spiral grooves, etc.) on an inner circumference ofthe passage 66 through the main body 60. With such an arrangement, themovement of the distal portion 84 of the proximal hub 80 and, thus, themovement of the obturator 50 (or another elongated instrument 100 (FIGS.7-8C) into and out of the distal end 24 of the cannula 20, may becontrolled (e.g., by rotation of the proximal hub 80 relative to themain body 60, etc.).

In some embodiments, the distal portion 84 of the proximal hub 80, theretaining ring 69 and/or the passage 66 through the main body 60 mayinclude one or more features 88, 68 that enable the proximal hub 80 tolock (rotationally and axially) in one or more positions (e.g., in aproximal position (i.e., with the obturator 50 or another elongatedinstrument 100 (FIGS. 7-8C) withdrawn (proximally) into the cannula 20),in one or more intermediate positions, in a distal position (i.e., withthe obturator 50 or another elongated instrument 100 fully extended(distally) from the cannula 20), etc.).

On its proximal side 82, the proximal hub 80 may include one or morecoupling features 83 configured to enable the percutaneous access system10 to be secured to another apparatus. Without limitation, the couplingfeatures 83 may comprise luer lock elements or other features that willenable the proximal hub 80 to be coupled to and uncoupled from acoupling element 53 with coupling features (not shown) at or near theproximal end 52 of the obturator 50 (FIG. 2), which correspond to thecoupling features 83 at the proximal side 82 of the proximal hub 80 andwhich may fix the obturator 50 in place relative to a remainder of thepercutaneous access system 10. Alternatively, or in addition, thecoupling features 83 may enable another apparatus, such as an elongatedinstrument 100 (FIGS. 7-8C), to be secured in place relative to theproximal hub 80.

While FIGS. 1-4, 3A and 4A illustrate an embodiment of percutaneousaccess system 10 that includes a conventional, straight obturator 50 ofa trocar, a percutaneous access system 10 according to this disclosuremay also be adapted for use with a bendable obturator and/or a steerableobturator.

Turning now to FIGS. 8A-8C, once a percutaneous access system 10 hasbeen used to access a desired location within a subject's body (e.g., ablood vessel, a cavity, etc.) and the distal end 24 of the cannula 20 ispositioned at a desired location within the subject's body, theobturator 50 (FIGS. 2, 3, 3A, 4 and 4A) may be proximally drawn into thedistal end 24 of the cannula 20 and removed (e.g., proximally withdrawn)from the internal passageway 30 through the cannula 20, from the channel76 (FIG. 2) through the distal hub 70 of the handle 40, from the passage66 (FIG. 2) through the main body 60 of the handle 40 and from thechannel 86 (FIG. 2) through the proximal hub 80 of the handle 40, whilethe distal end 24 of the cannula 20 remains in place within the body ofthe subject. Removal of the obturator 50 from the cannula 20 and itshandle 40 may make way for an elongated instrument 100, such as a wire,a sheath, a tube and/or a catheter, which may be used to further enablean elongated medical device (e.g., a catheter, etc.) to perform amedical procedure within the subject's body or to perform a medicalprocedure within the subject's body.

As illustrated by FIGS. 8A-8C, a percutaneous access system 10′ mayinclude a cannula 20, its handle 40 and an elongated instrument 100.With the distal end 24 of the cannula 20 of the percutaneous accesssystem 10′ at a desired location within the subject's body, a distal end104 of the elongated instrument 100 may be introduced into the handle 40through a proximal opening of the channel 86 (FIG. 1) that extendsthrough the proximal hub 80. As the elongated instrument 100 is pusheddistally into the handle 40, the distal end 104 of the elongatedinstrument 100 may move into and through the passage 66 (FIG. 1) throughthe main body 60 of the handle 40, into and through the channel 76(FIG. 1) through the distal hub 70 of the handle 40 and then into andthrough the cannula 20. The distal end 104 of the elongated instrument100 may then emerge from the distal end 24 of the cannula 20, at thedesired location within the subject's body. Alternatively, a healthcareprovider may distally push the elongated instrument 100 further, untilthe distal end 104 of the elongated instrument 100 is positioned at ornear a targeted location within the subject's body (e.g., a locationwhere a medical procedure is to take place, etc.).

Once the distal end 104 of the elongated instrument 100 is at thedesired location or the targeted location, a proximal end (not shown) oran intermediate location of the elongated instrument 100 may be securedin place relative to the proximal hub 80 of the handle 40 of thepercutaneous access system 10′. In some embodiments, the proximal hub 80of the handle 40 of the percutaneous access system 10′ may bemanipulated in a manner that causes an engagement feature associatedwith the proximal hub 80 to engage the elongated instrument 100 at alocation along a length of the elongated instrument 100. In a specificembodiment, the proximal hub 80 may be twisted about its access to causean engagement feature thereof (e.g., an o-ring, a compressible tube,etc.) to abut and engage an exterior surface of the elongated instrument100.

Alternatively, longer elongated instruments 100, including elongatedinstruments 100 that are to be introduced farther into a subject's bodythan is possible with the longitudinal movement provided by rotation ofthe proximal hub 80 relative to the main body 60 of the percutaneousaccess system 10′, may merely be inserted through the channel 86 (FIG.2) of the proximal hub 80, through the passage 66 (FIG. 2) through themain body 60, through the channel 76 of the distal hub 70 and throughthe internal passageway 30 (FIG. 2) that extends through the length ofthe cannula 20, which may enable manual longitudinal movement (e.g.,with a healthcare provider's hand, etc.) of the elongated instrument 50(FIGS. 1-3).

FIG. 8A shows the distal end 104 of the elongated instrument 100protruding a relatively short distance beyond the distal end 24 of thecannula 20. FIG. 8B shows the distal end 104 of the elongated instrument100 positioned a greater distance beyond the distal end of the cannula20. FIG. 8C provides a close-up view of a bent portion 101 of theelongated instrument 100 shown in FIG. 8B.

From the foregoing, various uses of the percutaneous access system 10,10′, as disclosed above, should be apparent to those of ordinary skillin the art. In one embodiment of use, with returned reference to FIGS.1-4, 3A and 3B, the distal end 54 of the obturator 50 may be insertedinto the proximal end of the channel 86 through the proximal hub 80,through the channel 86, into and through the passage 66 through the mainbody 60, into and through the channel 76 that extends through the distalhub 70 and into and partially through the internal passageway 30 of thecannula 20. With the obturator 50 positioned in this manner (see FIGS.2-4, 3A and 3B), the coupling element 53 at its proximal end 52 mayengage the coupling features 83 on the proximal side 82 of the proximalhub 80 to fix the obturator 50 in place relative to a remainder of thepercutaneous access system 10. With this arrangement, rotation of theproximal hub 80 relative to the main body 60 may enable the distal end54 of the obturator 50 to be moved distally into and through theexpandable section 25 of the cannula 20, and through the distal end 24of the cannula 20, as shown in FIGS. 2-4, 3A and 4A. With the obturator50 emerging or protruding from the distal end 24 of the cannula 20, itsdistal end 54 may be used to puncture the skin, another organ or othertissue of a subject. The distal end 24 of the cannula 20 may also beinserted into and through the subject's skin, another organ or othertissue. As the distal end 24 of the cannula 20 remains in place withinthe subject's body, in embodiments where the distal end 54 of theobturator 50 has been used to puncture a subject's skin, another organor other tissue, the obturator 50 may be proximally retracted (e.g., byrotating the proximal hub 80 in the appropriate direction relative tothe main body 60, etc.) and removed from the cannula 20 and the body 40.

With the distal end 24 of the cannula 20 remaining in position withinthe subject's body, another elongated instrument 100 (FIGS. 8A-8C) maybe used with the cannula 20 and its handle 40 for any of a variety ofmedical procedures, including, but not limited to, procedures thatrequire percutaneous access, such as vascular access procedures,laparoscopic procedures or the aspiration of fluid's from the subject'sbody (e.g., in biliary drainage, nephrostomy, abscess drainage anddrainage of other fluids from other locations and/or sources).

Although the foregoing description sets forth many specifics, theseshould not be construed as limiting the scope of any of the claims, butmerely as providing illustrations of some embodiments and variations ofelements or features of the disclosed subject matter. Other embodimentsof the disclosed subject matter may be devised which do not depart fromthe spirit or scope of any of the claims. Features from differentembodiments may be employed in combination. Accordingly, the scope ofeach claim is limited only by its plain language and the legalequivalents thereto.

What is claimed:
 1. A method for accessing a desired location within asubject's body, comprising: introducing a distal end of a cannula of thepercutaneous access device through skin of the subject to the desiredlocation, a proximal end of the cannula being fixed to a distal hub of ahandle of the percutaneous access device; and moving a proximal hub ofthe handle of the percutaneous access device proximally away from thedistal hub to withdraw an elongated instrument from the desired locationwhile the distal end of the cannula remains positioned at the desiredlocation.
 2. The method of claim 1, further comprising: introducing theelongated instrument into through the proximal hub, a remainder of thehandle, the distal hub, and the cannula.
 3. The method of claim 2,further comprising: coupling the proximal hub to the elongatedinstrument.
 4. The method of claim 3, further comprising: advancing theelongated instrument through the handle and the cannula to the desiredlocation.
 5. The method of claim 4, wherein advancing comprises movingthe proximal hub distally toward the distal hub.
 6. The method of claim5, wherein moving the proximal hub distally toward the distal hubcomprises rotatably advancing the elongated instrument through thecannula.
 7. The method of claim 1, wherein moving the proximal hub ofthe handle of the percutaneous access device comprises comprisesrotatably withdrawing the elongated instrument through the cannula. 8.The method of claim 1, wherein introducing the distal end of the cannulais accompanied by: introducing a distal portion of an obturator of apercutaneous access device through the skin of the subject to thedesired location within the body of the subject.
 9. The method of claim8, wherein introducing the distal end of the cannula comprisesintroducing the distal end of a cannula, through which the obturatorextends, through the skin of the subject to the site of interest. 10.The method of claim 8, wherein introducing the distal portion of theobturator comprises moving the proximal hub of the handle of thepercutaneous access device distally toward the distal hub.
 11. Themethod of claim 10, wherein moving the proximal hub of the handle of thepercutaneous access device comprises rotatably advancing the obturatorthrough the cannula.
 12. The method of claim 8, wherein moving theproximal hub of the handle of the percutaneous access device proximallyaway from the distal hub to withdraw the elongated instrument compriseswithdrawing the distal portion of the obturator from the desiredlocation.
 13. The method of claim 12, further comprising: withdrawingthe obturator from the handle.
 14. A method for accessing a desiredlocation within a subject's body, comprising: introducing a distal endof a cannula of the percutaneous access device through skin of thesubject to the desired location, a proximal end of the cannula beingfixed to a distal hub of a handle of the percutaneous access device; andmoving a proximal hub of the handle of the percutaneous access devicedistally toward the distal hub to advance an elongated instrument toand/or through the desired location while the distal end of the cannularemains positioned at the desired location.
 15. The method of claim 14,further comprising: introducing the elongated instrument into throughthe proximal hub, a remainder of the handle, the distal hub, and thecannula.
 16. The method of claim 15, further comprising: coupling theproximal hub to the elongated instrument.
 17. The method of claim 16,wherein advancing comprises moving the proximal hub distally toward thedistal hub.
 18. The method of claim 17, wherein moving the proximal hubdistally toward the distal hub comprises rotatably advancing theelongated instrument through the cannula.
 19. A method for accessing adesired location within a subject's body, comprising: introducing adistal end of a cannula of the percutaneous access device through skinof the subject to the desired location, a proximal end of the cannulabeing fixed to a distal hub of a handle of the percutaneous accessdevice; moving a proximal hub of the handle of the percutaneous accessdevice distally toward the distal hub to advance an elongated instrumentto and/or through the desired location while the distal end of thecannula remains positioned at the desired location; and moving theproximal hub proximally away from the distal hub to withdraw heelongated instrument from the desired location while the distal end ofthe cannula remains positioned at the desired location; and removing thedistal end of the cannula from the desired location.
 20. The method ofclaim 19, wherein at least one of moving the proximal hub of the handleof the percutaneous access device distally toward the distal hub andmoving the proximal hub proximally away from the distal hub comprisesrotating the elongated instrument.